L17- RTI VI Flashcards
list the three ways pneumonia is classified
- area of lung affected: lobar, bronchopneumonia, interstitial
- acquisition: CA, HA, ventilator associated
- causative agent: bacterial, viral, others (fungi)
list the common CA-pneumonia pathogens
- *S. pneumoniae
- *Mycoplasma pneumoniae
- *Chlamyodophila pneumoniae
- Haemophilus influenza
-Respiratory viruses (milder form, stems from URI)
list the common HA-pneumonia pathogens (differentiate by group)
(MDR- multi-drug resistant)
Non-MDR pathogens: *S. pneumoniae, H. influenzae, MSSA (meth. sens. S. aureus); Antibiotic-Sensitive Enterobacterieae: E. coli, *Klebsiella pneumoniae
MDR pathogens: *pseudomonas aeruginosa, MRSA; Anitbiotic Resistant Enterobacteriaceae
list the common causes of ‘typical’ pneumonia
- Strep. pneumoniae
- Klebsiella pneumoniae
- H. influenzae
- Staph. aureus
Clinical features of ‘typical’ pneumonia:
- (1) parts of lung involved
- (2) acute Sxs
- (3) signs of consolidation
1- one lobe affected
2- (acute onset) high fever, pleuritic chest pain, productive cough
3- dullness, vocal fremitus / resonance, egophony, whispered pectoriloquy, bronchial breath sounds
‘typical’ pneumonia:
- (1) list the phases
- (2) what are the diagnostic techiniques
1- i) consolidation, ii) red hepitization, iii) gray hepitization, iv) resolution
2- *CXR, sputum analysis, blood cultures
Strep. pneumoniae, aka (1), and causes the following infections, (2)
1- pneumococcus, diplococcus
2- pneumonia, sinusitis, otitis media
describe the distinguishing S. pneumoniae culture features
- α-hemolysis
- Optochin sensitive
describethe distinguishing S. pyogenes culture
- β-hemolysis (due to Streptolysin S)
- Bacitracin sensitive
- PYR+
(1) is the most common cause of CA-pneumonia. It is normally found in (2) and is transmitted in (3) fashion. Highest incidences are in the (4) season.
1- Strep. pneumoniae
2- nasopharyngeal flora (no animal / environmental reservoir)
3- endogenous OR exogenous person to person thru droplets
4- winter, early spring
S. pneumoniae has ______ as its hallmark symptom
rusty sputum: red-brown colored sputum
list the important virulence factors for S. pneumoniae
- Capsule: anti-phagocytic, evades immune response
- IgA protease
- Pneumolysin (many functions, on another slide)
- Autolysin
- Transformation
list the properties and functions of Pneumolysin found in S. pneumoniae
- inhibits ciliated epithelial cell activity
- *Cytotoxic for alveolar / epithelial cells
- causes inflammation + dec PMN effectiveness
list the pneumococcal pneumonia vaccinations and their indications
Pneumovax 23 (inactivated):
- 23 serotypes of different capsular polysaccharides
- for >65 y/o or smokers or those with certain medical conditions
Prevnar 13 (conjugated):
- 13 serotypes of capsular polysaccharides conjugated to a protein
- children <2y/o, adults >65y/o, or those with certain medical conditions
what is a key change to S. pneumoniae seen over the past few decades
significant inc in penicillin (and antibiotic) resistance (more than any other microbe)
Klebsiella pneumoniae:
- (1) family
- Gram(+/-) (coccus/bacillus) (un-/encapsulated) (non-/motile) (aerobe/anaerobe/facultative) catalase(+/-)
- (3) significance of lactose fermentation clinically
1- enterobacteriaeceae
2- Gram- bacillus, un-encapsulated (v. thick/large polysacharide), non-motile, facultative anaerobe, catalase+
3- it will appear pink on MacConkey’s agar
Klebsiella pneumoniae:
- (1) risks
- can cause (2) and (3) of the lung tissue, in part due to (4) virulence factor
1- alcoholics, DM, COPD, nosocomial infections (ventilators, catheters, etc) 2- necrotization of lung tissue 3- severe, destructive pneumonia (2/3 --> Necrotizing pneumonia) 4- LPS endotoxin
Klebsiella pneumoniae has _____ as its hallmark symptom
red currant jelly sputum: thick, viscous, sticky sputum mixed with blood
- *putrid odor to sputum and breath and in copious amounts in Necrotizing pneumonia
- contains: lots of bacteria, inflammatory cells, necrotic tissue
describe features of Necrotizing pneumonia (include alternate names)
-lung abscess / aspiration pneumonia
Defn: >1 area of lung parenchyma replaced by cavities filled with debris
-most are polymicrobial, including: Klebsiella pneumoniae (primary), S. aureus, anaerobes/microaerophiles from mouth flora
Klebsiella pneumoniae:
- (1) method of transmission
- (2) Fe uptake systems
- (3) and (4) are main immune evasion virulence factors
- (5) are key in initiation of infection
- (6) protein key for bacterial resistance
1- person to person contamination only (not thru air)
2- aerobactin, enterochelin
3- thick polysaccharide capsule, CPS/K Ag
4- LPS, O Ag (prevents phagocytosis, impedes C3b and opsonization)
5- pili / fimbriae –> attachment and biofilm formation
6- carbapenemase => carbapenem resistance
Pseudomonas spp., mainly (1) species, is considered a (2) pathogen found in (3). The most common infection it causes is (4).
1- P. aeruginosa
2- environmental opportunist (people with weak immunity)
3- still fresh water sources (ubiquitous)
4- otitis externa / swimmer’s ear
what people are at highest risk of Pseudomonas aeruginosa
- burn victims
- CF Pts (abnormal mucus obtructs airways => chronic lung infections)
- HA infections
(1) is the most common Pseudomonas infection, mostly in the (2) season and in people with (3) risks.
1- otitis externa
2- summer
3- swimming, trauma, dermatologic conditions
describe the general pathogenesis of an otitis externa infection
- breakdown of skin-cerumen barrier
- -> inflammation of skin
- -> pruritis + obstruction
- -> scratching
- -> cerumen quality/quanity altered
- -> inc pH = warm, alkaline, moist ear canal
- -> microorganism growth
list the symptoms of otitis externa (include otoscopy exam)
- ear pain, pruritus, discharge
- hearing loss
- erythema around auricle/tragus
- tenderness of auricle/tragus during manipulation in otoscopy
Otoscopy: edema, erythema, debris, inflamed TM
Pseudomonas aeruginosa affects (1) patients the most to cause (2) because of the (3) property of (1) disease. (2) infections in (1) patients are characterized by (4) type microbes in general.
1- CF pts
2- necrotizing bronchial pneumonia
3- abnormal mucus production –> ready made biofilm
4- permanent highly drug resistant infections –> often fatal
Pseudomonas aeruginosa:
- Gram(+/-) (coccus/bacillus) (aerobe/anaerobe/facultative) (non-/motile)
- (2) result on blood agar
- colonies are described as (3), and can have a (4) color
- (5) is a unique distinguishing characteristic
1- Gram- bacillus, aerobe (strictly), highly motile (multiple flagella)
2- β and γ hemolysis
3- mucoid colonies
4- green color due to pyocyanin, fluorescein
5- smell (peculiar scent, described as grape-like)
Pseudomonas aeruginosa has ______ as its hallmark symptom
yellow-green sputum production
Determine the infecting pathogen for pneumonias with the following sputums:
- (1) red currant jelly sputum
- (2) rusty sputum
- (3) yellow-green sputum
1- klebsiella pneumoniae
2- strep. pneumoniae
3- pseudomonas aeruginosa
list the most common pathogens of ‘atypical’ pneumonia
(aka walking pneumonia)
Prokaryotes:
*mycoplasma spp., *chlamydophila pneumoniae, *legionella pneumophila
30-40% of all CA-pneumonias
decribe the difference in symptoms seen in atypical pneumonia
-gradual and insidious onset (days to wks)
Milder Sxs:
- mild fever
- exertional SOB
- dry/mild productive persistent cough
- scratchy sore throat (mycoplasma spp.)
- pleuritic chest pain
- HA, myalgia, arthralgias
- loss of appetite, low energy / fatigue
what are the unique symptoms seen in atypical pneumonia due to Legionella pneumonphila
- confusion
- GI Sxs
- hyponatremia
Mycoplasma pneumoniae:
- (1) shape
- (2) cell wall characteristics
- intrinsic resistance to (3)
- (non-/motile)
1- short rod (lacks rigid cell wall)
2- absent, unreactive to Gram staining
3- β-lactams
4- gliding motility
Mycoplasma pneumoniae virulence factors:
- (1) for specialized attachment
- (2) production => tissue destruction
- (3) => cytotoxic effect on respiratory epithelium during acute infection
1- P1 adhesin, accessory proteins
2- H2O2
3- CA-respiratory distress syndrome toxin
Mycoplasma pneumoniae pathogenesis:
- (1) route of transmission
- inhibition of ciliary movement leads to (2)
- attaches to / damages the (3) part of respiratory epithelial cells to activate immune response
(4) and (5) are the key properties that correlate with its pathogenicity
1- airborne droplets, person-to-person
2- prolonged paroxysmal cough
3- base of cilia on epithelium
4- selective affinity for respiratory epithelial cells
5- H2O2 production => initial cell disruption in RT –> damages erythrocyte membranes
explain Mycoplasma pneumoniae diagnosis process
*NAAT’s: PCR, multiplex PCR
Serology:
- serum cold agglutination: neg. result mean f/u with PCR to confirm
- > 4-fold inc/dec in titers
Mycoplasma pneumoniae:
- (1) prognosis
- (2) prevention strategies
1- usually full recovery w/ Tx
2- (no vaccine) avoid close contact, prophylactic Tx w/ h/o contact + usual URI precautions
